1. Field of the Invention
The present invention is in the technical field of improving the capability of equipment for usage in space, atmospheric, oceanic and terrestrial exploration through usage of compositions and materials that suppress stray light and provide enhanced emittance. The principles of the present invention are applicable to any imaging or image projecting system for commercial or scientific use.
2. Description of Related Art
The exploration of space requires equipment with ever-increasing sensitivities to uncover further mysteries of the Universe and its workings. Whether telescopes or other observational instrumentation, the problems of stray light interfering with the performance of these delicate devices are prevalent. Various paints and coatings have helped to absorb stray photons, thereby minimizing some of the ill-effects of this radiation, but further improvements are needed to conquer this deleterious situation for astronomical observation and other measures. Likewise, various atmospheric and terrestrially-based apparatus suffer the same problems.
For example, scientific instrument performance can be limited by stray light from bright sources adjacent to dim objects under observation. A darker material to suppress this stray light has multiple benefits to these observations, including a) enabling scientific observations not currently possible, b) increasing observational efficiencies in high contrast scenes, and c) simplifying instruments and lowering their cost by utilizing fewer stray light components and achieving equivalent performance. Bright objects, such as clouds or ice, scatter light off of instrument structures and components and make it difficult to see dim objects from Earth. Similarly, bright stars or celestial objects can scatter light and compromise the ability to view adjacent dim objects.
One technique employed by the prior art is to use black paints, such as Aeroglaze Z306, on satellites and other equipment to suppress the stray light. This and other prior techniques, however, result in at best approximately 4% of the light being reflected, as determined by hemispherical reflectance or total integrated scatter (TIS), described in more detail hereinbelow.
Another problem related to the above is the need for such coatings to be firmly part of a structural component of the equipment, such as apertures, tubes, stops and baffles, since coatings may degrade and fall off in extreme environments, such as in space, oceanic or atmospheric research.
The National Aeronautics and Space Administration (NASA) has been at the forefront of technology for such developments. With the diverse needs of current and upcoming NASA space research, there is a growing need for equipment that has better stray light suppression for use in space, oceanic, atmospheric and terrestrial instrumentation.
Carbon nanotubes, known for their strength, are also black, and offer the possibility for use in suppressing stray light. However, existing techniques grow the carbon nanotubes on a silicon substrate, which is a poor material for numerous stray light components, such as tubes, stops and baffles, due to its more delicate compositional structure. In addition to light suppression, there is a need for materials that provide emittance control for radiating away heat and energy.
There is, therefore, a need for systems, equipment, compositions and methods that provide stray light suppression capabilities, that these coatings better bond to the substrate materials, that the substrate material be strong, and that the combination be able to function properly in difficult and extreme situations and environments.